The installation of a conventional propulsion system in an inboard motor or engine powered water craft is a source of many problems. For example, the task is very time consuming and requires relatively highly skilled labor, and, even where considerable care is taken, the finished product often suffers mechanical problems, particularly with respect to the alignment provided between the various components including the engine, propeller shaft, and shaft bearing.
One approach to solving this problem involves the use of integrated propulsion and steering units, and a number of different propulsion and steering assemblies have been developed wherein the basic components are formed as a one-piece or integrated unit in order to eliminate alignment problems associated with prior art assemblies that arise when the different components are assembled together during manufacture or outfitting of the basic boat. Reference is made, for example, to U.S. Pat. No. 3,003,458 (Starns, Jr.) wherein an inboard boat propulsion and steering assembly is disclosed which includes a propeller shaft "log" or housing, a mounting plate, a rudder shaft "log" or housing and a downwardly depending shaft support strut carrying a propeller shaft bearing, all formed as an integral unit. It will be appreciated that this integral unit inherently provides proper alignment between the propeller shaft log and the propeller shaft bearing. The integral unit, with the propeller shaft and rudder inserted therein, can be installed as one piece, and when the unit is installed, only installation, alignment and connection of the engine and mounting of the propeller on the propeller shaft remain in order to complete the propulsion and steering assembly. Other examples of integrated units of this general type include U.S. Pat. Nos. 2,064,463 (Crosley, Jr.); 2,630,094 (Hacker); 2,895,446 (Upton); 2,934,034 (Grzesnikowski); 4,040,378 (Blanchard); 4,046,096 (Liaaen); and 4,236,478 (Mansson). One serious disadvantage of such units is that when damage occurs the entire unit generally must be replaced.